foods = ('cabbage','egg','fish','meat','chicken') #定义元组
for food in foods:
    print(food)
print(foods)
#foods[0] = 'cake'   这样写是错误的
#print(foods)
foods = ('pizzas','cake','fish','ment','chicken') #重定义整个元组，修改元组变量
for food in foods:
    print(food)
print(foods)